For analyzing the exhaust gases of an internal combustion engine the present inventor, in U.S. Pat. No. 3,999,425, has proposed a device, which includes a mechanical unit actuating the fuel supply means of the engine, as well as means for branching-off a portion of the total volume of exhaust gas, and conveying this branched-off portion to an analyzing apparatus, or to a container suitable for transporting gas to the analyzing apparatus. The engine is disconnected from the power transfer means and is permitted to run at idling speed, and it is presupposed that the mechanical actuating unit is governed by a monitoring device, which is programmed to cause, during a pre-determined period of time a number of variations in the fuel supply to the engine, to simulate various driving conditions. As the internal losses and the inertia of the engine are the only load imposed upon the engine the testing sequence will be determined by the relationship between speed, momentary acceleration or retardation against inertia and internal losses, as well as equilibrium conditions at constant speed in pre-determined proportions and sequences.
It is evident that equipment which must be used for analyzing the exhaust gases from engines of different types, must be adjustable to suit the characteristics of different engines. Even engines within the same series, and having the same nominal output may differ after some time of use. It is therefore advantageous that the device includes means making it possible, in a simple manner, rapidly to adjust the same to the condition of an actual engine, the exhaust gases of which are to be analyzed.